Beef and Vegetables

• 2 lbs beef chuck, cut into cubes
• 2 tablespoons olive oil
• 2 tablespoons unsalted butter
• 1 large onion, finely chopped
• 3 cloves garlic, minced
• 3 large carrots, peeled and chopped
• 3 medium potatoes, peeled and cubed
• 2 stalks celery, sliced
• 2 tablespoons tomato paste
• 2 tablespoons all-purpose flour
• 11.2 oz Guinness stout
• 3 cups beef broth
• 1 tablespoon Worcestershire sauce
• 1 teaspoon dried thyme
• 1 teaspoon dried rosemary
• 2 bay leaves
• 1 teaspoon salt
• ½ teaspoon black pepper
• 1 teaspoon sugar, optional
• 2 tablespoons fresh parsley, chopped